Various arrays for a color filter array mounted on a solid-state imaging device have been proposed and used. For example, in an imaging apparatus described in Patent Document 1 indicated below, a color filter array called a Bayer array is used. In the Bayer array, color filters of any one of three primary colors of R (red), G (green) and B (blue) are arranged in a mosaic pattern. In the Bayer array, for example, a red pixel mounted with a red color filter cannot detect the green and blue signals. Therefore, a signal of a pixel mounted with a green color filter or a blue color filter and arranged around the red pixel is interpolated to acquire a green signal or a blue signal for the red pixel location.
In a solid-state imaging device described in Patent Document 2 indicated below, two pixels adjacent to each other in a slanted direction are grouped as a pair and color filters of any one of RGB are arranged in a unit of the paired pixels in a mosaic pattern. Therefore, for example, each pixel of the pair mounted with a green color filter is mounted with a G1 color filter or a G2 color filter.
In the relationship between the G1 and the G2, for example, the G1 and G2 are selected so that when the G1 and G2 are added, the G color is produced. A color filter of G color is manufactured to have a bell-shaped spectral characteristic having a width of about 100 nm in each of the forward and rearward directions for a center wavelength of 540 nm. On the other hand, for example, the G1 and G2 separate the bell-shaped spectral characteristic, such that the G1 color filter detects a color with a wavelength of 440 nm to 540 nm and G2 color filter detects a color with a wavelength of 540 nm to 640 nm. Similarly, for R color or B color, paired pixels are mounted with R1 and R2 color filters and B1 and B2 color filters, respectively.
In this manner, colors to be separated by color filters are more finely separated than three colors of RGB, such that the color reproducibility of the subject image can be improved.
In an imaging apparatus described in Patent document 3 indicated below, the respective pixels are divided into a large area part and a small area part. Furthermore, for example, in a pixel mounted with a green (G) filter, a filter thickness laminated on the small area part is thicker than that of the large area part or a thickness of n region constituting a photodiode is set to be thinner.
As a result, an incident light within a predetermined wavelength range substantially cannot be detected in the small area part while the light within the predetermined wavelength range can be detected in the large area part. By doing this, the imaging apparatus detects of whether there is light within the predetermined wavelength range or not to determine a type of light source.